(a) Field of the Invention
The invention relates to a plasma display panel device. More specifically, the invention relates to an image data correction method and apparatus for amending image data while maintaining chromaticity of video signals and constant white linearity, and a plasma display panel device having the apparatus.
(b) Description of the Related Art
The plasma display panel is a display device that has a plurality of discharge cells arranged in a matrix form, which are selectively excited to emit light and thereby to reconstitute image data originally input as electrical signals.
Gray-scale representation must be achieved on the PDP for improved performance of the PDP as a color display device. A gray-scale representation method divides one field into a plurality of subfields and subjects the subfields to time division control to achieve gray-scale representation by the subfields.
The number of subfields is fixed irrespective of image data in a general gray-scale representation method. However, a gray-scale representation method using a variable subfield method determines the number of subfields according to the average signal level (hereinafter, referred to as “ASL”) of 1-field image signals, and maps input image data in a memory according to the number of subfields.
Gamma correction and error propagation processing are performed on the input image signals. Namely, digital image data undergo gamma-value correction based on the characteristics of the PDP, and at the same time, display errors undergo propagation processing for the surrounding pixels.
Now, the prior art will be described with reference to an accompanying drawing.
FIG. 1A shows a comparison of the weights of a red fluorescent body with application of image gamma between the cases where the number of subfields is 10 and where the number of subfields is 12. FIG. 1B shows a comparison of the weights of a red fluorescent body without application of image gamma between the cases where the number of subfields is 10 and where the number of subfields is 12.
Referring to FIGS. 1A and 1B, the luminescence characteristic of the fluorescent body differs by APC (Automatic Power Control) levels according to the number of subfields.
Conventionally, the luminescence characteristic of RGB varying by subfields is not reflected on the gamma correction, and accordingly, image data are falsely corrected.